Characterization of peptidases of adultTrichuris muris

Abstract

Excretory/secretory (E/S) material of Trichuris muris was found to contain 2 major peptidases, M(r) 85 and 105 kDa, which degrade gelatin optimally at pH 6.0 in sodium dodecyl sulphate-polyacrylamide gels. The peptidases were inactivated by diisopropylfluorophosphate, leupeptin and soybean trypsin inhibitor, but were unaffected by inhibitors of aspartic-, cysteine- and metallo-peptidases, indicating that they are serine peptidases. Both enzymes were detectable within 5 h after incubation of worms in culture medium and showed a time-dependent increase in levels. Neither peptidase was detected in worm extracts, suggesting that they are activated during or following secretion from worms. Live worms degraded a radio-isotope labelled extracellular matrix protein substratum derived from mammalian cells. Aminopeptidase activities capable of catalysing hydrolysis of amino acyl aminomethylcoumarin (MCA) substrates and a Z-Phe-Arg-MCA-hydrolysing cysteine peptidase activity, were detected in extracts of adult worms but not in E/S material.

Genome and transcriptome of the porcine whipworm Trichuris suis

“…We predicted 618 canonical excretory-secretory (ES) proteins in adult T. suis (Supplementary Tables 14 and 15), including 165 proteases, many of which might have a role in disrupting intestinal epithelial cells in the host 19,20 and in the formation of the syncytial tunnel around the Trichuris stichosome 21 . Notable among these molecules are 33 chymotrypsin-like serine proteases, which play key roles in helminths associated with host invasion 22 , immuno-suppression 23 and tissue destruction 24 .…”

Characterization of Trichuris muris secreted proteins and extracellular vesicles provides new insights into host–parasite communication

“…These proteins could be involved in extracellular digestion, and, since feeding is a key process in parasite biology, they might also be potential targets for vaccines and drugs against the parasite. Helminth proteases have also been hypothesized to be involved in immunomodulatory processes, where they degrade important immune cell surface receptors [65] and host intestinal mucins [9,66]. If this is the case, Trichuris could be secreting EVs containing peptidases to promote an optimal environment for attaching to the mucosa and feeding purposes.…”

Enzymology of the nematode cuticle: A potential drug target?

“…Serine proteases are implicated in the processing of cuticular proteins during moulting and development (see collagen N-terminal processing section), and serine protease inhibitors may regulate or control this class of proteases (Drake et al, 1994). A serine protease inhibitor ( Ov -SPI-1) was identified in the L3 stage of O. volvulus , with expression increasing in the moulting larvae and adults.…”